Fluid dispersing checkvalve

ABSTRACT

A checkvalve is provided for dispersing a fluid into a flowing stream. All operating parts of the checkvalve are located in the flowing stream to provide uniform and rapid dispersion of the fluid.

FIELD OF THE INVENTION

This invention relates to a checkvalve for dispersing a fluid into aflowing stream. More particularly this invention relates to a checkvalveuseful in dispersing agricultural chemicals into a stream of irrigationwater.

BACKGROUND OF THE INVENTION

In recent years a method for adding agricultural chemicals to farmlandhas developed. This method commonly known as “chemigation” involves theintroduction of the agricultural chemicals into irrigation water withsubsequent dispersion of the irrigation water containing the chemicalsonto the cropland. Chemicals such as fertilizers, insecticide,herbicides, etc. can dispersed by this method. In order to be effective,the chemical must be well dispersed in the irrigation water prior to thewater being sprayed upon the cropland. Care must be taken in order toassure that in the event of a shutdown in the flow of irrigation waterthe chemical will not flow into the water source causing contaminationof the source of water. Also, it is necessary that irrigation water doesnot flow into the chemical supply system causing overflow and areacontamination.

Although some agricultural chemicals are soluble in water, it is alsodesirable to effectively disperse chemicals which are not readilysoluble or are insoluble in water. These chemicals are often supplieddissolved in a water insoluble solvent such as kerosene. Certainchemicals such as fertilizers can also be available as a slurry ofsolids in a liquid. Therefore, it is desirable to effectively disperse awater insoluble (or minimally soluble) material into a stream ofirrigation water.

A number of valve systems have been suggested the prior art. Savage inU.S. Pat No. 3,267,959 (1966) discloses a valve which is said tofunction as an anti-fouling and anti-siphoning valve in irrigationsystem. The valve is provided with a neck portion which designed toextend into the liquid stream being treated so that the chemicals beingdischarged will be “immediately absorbed by the liquid and removed fromthe position of the valve proper”. The valve is designed to open whenthe chemical being injected is subjected to pressure equal to or greaterthan the sum of the pressure of the fluid flowing in the pipe into whichthe valve extends. An array of slots is provided in the tip portion sothat when the chemical flows past the O-ring seal, the chemical candisperse through the slots thereby providing an early release ofdischarge pressure to avoid dislodging the O-ring seal. This valve has asignificant disadvantage in that, when the flow rate of the chemical isincreased and the valve member containing the O-ring travels past theend of the housing containing the slots, the valve stem can be subjectedto a significant lateral force as the result of the flow of the liquidstream past the valve. This lateral force can bend the valve stemresulting in failure of the O-ring valve to seat properly. Deflection ofthe extended valve stem can also result in the valve jammping open.Either effect will allow the chemical to continue to leak into thesystem, or allow liquid in the conduit to pass through the check-valveback to the source of the chemical.

Gilroy in U.S. Pat No. 4,437,611 (1984) discloses a spray nozzle to beused in a sprinkler system in a corrosive or dirty environment. Thespray nozzle is designed to be mounted in a conduit wall essentiallyflush with the inside of the conduit into which a spry of liquid is tobe provided. This nozzle has a disadvantage that the moving parts arecontinually bathed in the chemical being injected. Since many of thechemicals used in agriculture are corrosive, special materials must beused to avoid corrosion and plugging of the valve. Additionally,introduction of the chemical along the conduit wall does not provide foroptimum dispersion of the chemical into the flowing stream.

In a series of three patents, Stamps et al., disclose a method andapparatus for dispersing substantially water soluble agriculturalchemicals into an irrigation system. This method involves dispersing thechemical by passing a pressurized stream containing the chemical throughan orifice. The dispersed stream passes through a checkvalve andsubsequently through an entry line, which projects into the waterstream. This procedure has the disadvantage of requiring a substantialamount of additional equipment in order to effectively disperse thechemical into a stream which must then be dispersed into the mainirrigation stream. U.S. Pat. Nos. 3,464,626 (1969), 3,326,232 (1967),and 3,375,976 (1968).

None of these references disclose a device capable of effectivelydispersing a fluid at a variety of flow rates into a moving stream ofliquid. All of these referenced devices and methods have thedisadvantages disclosed hereinabove. Accordingly, there is a need for anapparatus which can effectively disperse a fluid into a stream of aliquid while also serving as a checkvalve to avoid unintentional flow ofthe fluid into the liquid or the liquid back into the source of thefluid.

SUMMARY OF THE INVENTION

It has been found that the above described disadvantages can be overcomewith the checkvalve of the instant invention. The instant fluiddispersing checkvalve comprises a conduit having a passage extendinglongitudinally therethrough. The passage has an inlet end and an outletend, and an orifice is located at the outlet end of the passage. Aslotted housing which has a first end is attached to the outlet end ofthe conduit. A valve seat circumscribes the orifice. A valve which isadapted to reside in said valve seat is slidably located in the housing.A valve retainer, is also slidably mounted in the housing to urge thevalve into contact with the valve sea. A spring means is located in thehousing and is operatively connected to the valve retainer to yieldinglyurge the retainer into contact with the valve to provide a seal when thevalve resides in the valve sea. The spring means is held in place in thehousing by a spring retainer which is fixed to the second end of thehousing and engages the spring means.

In another embodiment, the instant invention comprises a method fordispersing a fluid into a liquid stream. The fluid flows through apassage in a conduit and exits through an orifice. The exiting fluiddisplaces a valve from a valve seat which surrounds the orifice. Thevalve is urged against a valve retainer moving the valve retainer andvalve longitudinally in a slotted housing away from the orifice. Thevalve retainer, is moved in opposition to a spring means compressing thespring means. The exiting fluid flows past the valve and is dispersedthrough slots in the slotted housing into the liquid stream. Upontermination of the flow of fluid, the compressed spring means acts toreturn the valve retainer and valve to provide contact between the valveand the valve seat and seal the orifice.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows an exploded view of the device of the instant invention;

FIG. 2 shows another embodiment of the valve and the valve retainer; and

FIG. 3 represents the operation of another embodiment of the instantinvention in which the valve is inserted into the steam stream at anangle of less than 90° to the internal pipe surface.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIG. 1, a preferred embodiment of the instantcheckvalve is depicted in exploded form. Conduit 2 is shown having afitting 4 on one end and a housing 6 on the other. A passage 8 passeslongitudinally through the conduit 2 and terminates in a orifice 10 atthe outlet end of the conduit. Surrounding the orifice is a valve seat12. A valve 14 is urged against the valve seat 12 by a valve retainer 16and spring means 18. The spring means is retained in the housing 6 by aspring retainer means 20. The valve, valve retainer and spring means areall slidably contained within said housing 6.

In order to provide the desired rapid dispersion of the fluid into aflowing stream, it is preferred that the conduit 2 be of such a lengthas to locate the housing 6 in approximately the center of teh theflowing stream. Locating the housing in the liquid stream allows liquidto flow around the moving parts of the checkvalve, i.e. the valve, valveretainer and spring means, as well as the valve seat and orifice. Theflowing liquid stream serves to rapidly remove the chemical from thesepalls and prevent accumulation of the chemical which can cause jammingor freezing of the checkvalve. Although conduit 2 is depicted as beingstraight in FIG. 1, it can be formed to have an angle of up to about 90°compared to the straight embodiment.

The housing 6 contains valve 14, valve retainer 16 and spring means 18.The interior of the housing acts as a channel in which these parts move.Although it is preferred that the housing be substantially cylindricalin shape, other configurations are contemplated as functioningequivalently. For example, housings having the lateral cross-section ofa square, rectangle, ellipse, etc. function satisfactorily and aretherefore considered to be within the scope of the instant invention.

In making the valve, it is preferred that the housing and conduit bemolded as one piece. The housing 6 can be fixed to conduit 2 by anyappropriate means. For example, the housing can be glued, screwed orwelded onto said conduit depending on the materials of construction.

The housing 6 is provided with a plurality of openings or slots 21.These openings in the housing allow the fluid passing from the orificeto rapidly disperse in the stream. The term “slot” as used hereincontemplates a variety of equivalent configurations which can accomplishthis dispersion. For example, holes, squares, rectangles, spiralopenings, etc., can be used. It is preferred that the slots occupy asmuch of the surface area of the housing as possible in order to allowthorough dispersion of the fluid into the stream. However, it is alsonecessary that there be sufficient surface on the housing to have therequired strength to retain the spring and valve within. Also, it isnecessary that there be sufficient surface area to provide a guidingpath for movement of the valve 14 and valve retainer 16 within thehousing.

As discussed previously, the housing 6 provides a channel for movementof the valve and valve retainer as they are acted upon by the pressureof the fluid and the tension of the spring means 18. It is preferredthat the valve 14 and valve retainer 16 have minimal lateral movementwithin the housing to avoid binding and jamming with subsequent loss offunction of the check valve. Therefore, in the embodiment shown in FIG.1, it is preferred that the outside edges of the valve contact theinside surface of the housing. The valve retainer must freely movelongitudinally within the housing, but should be sized to minimizelateral movement.

The valve 14 should seal against the sides of the slotted housing 6 inorder to maintain the most efficient mixing of the fluid. To maintainmaximum mixing efficiency it is preferred that the valve be of solidconstruction, i.e. not contain an aperture such as an O-ring in order toavoid “riding” of the valve when a valve retainer as depicted in FIG. 1is used. As discussed herein-below, an O-ring can be used with adifferent valve retainer configuration. The valve must be capable ofeffectively sealing to prevent movement of the fluid from the orificewhen the valve is in contact with the valve seat. It must also havesufficient structural integrity to avoid distortion as the result offluid or stream pressure. Preferable materials of construction includeviton, neoprene, Buna-N rubber and teflon. It has been found that athickness of at least about ⅛ of an inch is sufficient to minimize thepressure distortion problems and provide an adequate seal.

The valve retainer 16 contacts the valve 14 at the urging of springmeans 18 and forces the valve 14 into intimate contact with valve seat12. A preferred configuration of the valve retainer is shown in FIG. 1.When a solid valve is used, it is preferred that the valve retainer havea flat surface for contacting the valve. Preferably, the valve retaineralso conveniently has an elongated member which the spring means 18 fitsaround. This serves to keep the spring means centered on the valveretainer to provide even pressure on the valve 14. Alternatively, thespring means can be attached to the valve retainer and the elongatedmember eliminated.

It is possible to use O-ring type valves provided they are attached tothe valve retainer 16 to avoid the “riding” of the valve discussedhereinabove. One such embodiment, depicted in FIG. 2 (elongated membernot shown), is a conical shaped valve retainer adapted to contact afemale conically shaped valve seat. An O-ring valve can be providedaround the perimeter of the valve retainer to seal the flow of fluidwhen the valve contacts the valve seat. It is also contemplated that thesurface of the valve retainer can be grooved in order to provide abetter dispersion of the fluid.

Referring again to FIG. 1, the spring means 18 urges the valve retainer16 to maintain the valve 14 in intimate, sealing contact with the valveseat 12. This prevents any significant flow of fluid out of the orifice10 or any of the stream from flowing into the passage 8. The tension ofthe spring means 18 is selected to provide a pressure sufficient tocause valve 14 to seal when fluid is not being pumped through passage 8.Although the spring means 18 can exert a pressure less than the stream,it is preferred that the spring means have a tension of at least 2pounds per square inch greater than the stream pressure in order toconveniently calibrate the delivery rate of the pump means being used todeliver fluid through passage 8. More preferably, the tension is atleast 5 pounds per square inch greater, e.g. if the stream has apressure of 50 psig, it is preferred that the spring means have atension which will exert at least about 55 psig. Ordinarily, if it isdesired that smaller fluid droplets be formed, the differential betweenthe pressure exerted by the spring means and the stream pressure shouldbe greater, i.e. the tension of the spring means should be greater thanthe stream pressure.

The spring retainer means 20 holds the spring means in place in thehousing. The spring retainer means is affixed to the end of the housingopposite the orifice. The spring retainer means can be affixed by beinginserted into locking channels 22 such as shown in FIG. 1 although otherchannel configurations can be used; it can be screwed onto the end ofthe housing; it can be compression fitted or thermally welded; or it canbe attached by any other suitable method. A preferred method is shown inFIG. 1 since this allows easy removal and replacement of the springmeans and/or valve 14.

The valve of the instant invention can readily disperse a fluid flow aslow as 0.1 gallon per hour up to a flow rate as high as about 130gallons per hour. For flow rates in the range of about 0.1 to about 35gallons per hour, an orifice in the range of about 0.125 inch can beused to provide satisfactory results. For flow rates in the range ofabout 35 to about 130 gallons per hour, an orifice in the range of about0.250 inch is preferably used.

The instant checkvalve can be constructed from any materials having thesuitable chemical resistance and strength. The design of the instantcheckvalve allows the use of lower strength and less resistant materialsfor constructing the spring means, valve retainer and housing than priorart valves. In the instant checkvalve, the moving stream of liquidconstantly washes these parts free of any corrosive chemical. Also, thevalve retainer is not subjected to severe lateral forces as in theSavage valve, Thermoplastic resins can be used in construction of theconduit 2, fitting 4, housing 6, valve retainer 16 and spring retainermeans 20. It is preferred that reinforced resins be used in order toprovide additional strength, for example, glass reinforced polyolefins,polyesters, polyamides can be used. It is preferred that the conduit 2,fitting 4, and housing 6 be prepared in one piece preferably byinjection molding. Since the spring means is located in the flowingstream instead of residing in the chemical fluid, the material ofconstruction does not have to be of a special non-corrosive material asit does in prior art devices. However, for longer lifetime, thepreferred materials of construction include stainless steel, Hastelloyalloys, etc.

Although the instant checkvalve has preferred utility in addingagricultural chemicals to a stream of irrigation water, the checkvalvecan also be used to introduce and disperse essentially any fluid into amoving liquid stream. Accordingly, it is not intended that thisinvention be limited to the chemigation field. For convenience ofexplanation, the instant checkvalve is discussed in terms of theaddition of agricultural chemicals to a stream of irrigation water.However, it is expected that other uses can be readily determined whichinvolve the addition of a fluid to a moving stream of liquid. Theinstant checkvalve has the advantage of providing significant dispersionof a fluid in a stream which does not have turbulent flow.

As used herein the term “fluid” refers to liquid liquids includingemulsions, gases and slurries of finely divided particulates suspendedin a liquid. In order to be used in the instant checkvalve, theparticulates in such a slurry must be small enough to readily passthrough the orifice. Ordinarily the largest particulate in such a slurryshould be less than about one-tenth the diameter of the orifice.

In an agricultural operation, the valve is inserted into an opening inan irrigation pipe through which the stream of irrigation water ispassed. A preferred method of attaching the valve is to provide athreaded connector 24 in the side of the pipe as shown in FIG. 3. Athreaded fitting 4 on one end of the conduit 2 can be used to attach thevalve to the pipe. The connector 24 can be affixed to the pipe in anyconvenient manner, ordinarily by welding. It can be attached squarely onthe pipe, i.e, at 90° or can be angled as shown in FIG. 3. Thus thecheckvalve can be inserted into the pipe so that conduit 2 is straight(i.e. 90°) or at an angle between about 0° and about 45° compared to thelongitudinal axis of the pipe. Having the conduit 2 at an angle of lessthan 90° to the longitudinal axis of the pipe provides better dispersionof the chemical into the flowing stream. This can be accomplished byusing an angled conduit 2 as discussed hereinabove, or by affixingconnector 24 at an angle, or a combination of the two.

Before the pressure on the chemical fluid is increased, the spring means18 urges the valve retainer 16 against valve 14 to seal orifice 10 andprevent any of the water or irrigation stream from passing into passage8 or any of the chemical in passage 8 from escaping into the waterstream. As the pressure of the chemical fluid is increased, it willeventually equal the greater of the pressure provided by the springmeans 18 or the irrigation stream. At this point, chemical fluid canescape past the valve 14 into the irrigation stream. Since the pressureof the chemical fluid is greater than the pressure of the stream, nowater flows from the stream into passage 8. As the chemical passesthrough orifice 10 and past valve 14, it is rapidly dispersed in theirrigation stream through slots 21. The difference in pressure betweenthe chemical fluid and the irrigation stream serves to break the fluidinto small particles which are rapidly dispersed in the stream. As thepressure on the chemical is increased, the spring means 18 is furthercompressed and a greater volume of chemical passes through the orifice10 and into the irrigation stream. In the event the flow of chemical isterminated, the pressure on valve 14 from the chemical is terminated andspring means 18 immediately acts to force valve 14 against valve seat 12sealing the orifice and preventing the passage of material from theirrigation stream into passage 8.

A variety of agricultural chemicals such as fertilizers, pesticides,fungicides, insecticides, and herbicides can be dispersed into a streamof irrigation water using the instant checkvalve. The chemicals can bein the form of solutions, emulsions, suspensions or colloids.

It will be understood that the above description of the presentinvention is susceptible to various modifications, changes andadaptations and the same are intended to be comprehended within themeaning and range of equivalents of the appended claims.

What is claimed is:
 1. A checkvalve for dispersing a fluid into a streamof liquid said checkvalve comprising: (a) a conduit having a passageextending longitudinally therethrough, said passage providing an inletend and an outlet end to said conduit; (b) an orifice located at theoutlet end of said passage; (d)(c) a housing having a first end fixed tothe outlet end of said conduit, said housing having a plurality ofslotsopenings extending substantially the length of said housing toallow a portion of the liquid flowing past said housing to flow throughsaid housing; (d) a valve seat within said housing circumscribing saidorifice; (e) a valve slidably mounted in said housing and adapted toreside in said valve seat; (f) a valve retainer slidably mounted in saidhousing and adapted to urge said valve against said valve seat; (g) aspring means in said housing operatively connected to said valveretainer to yieldingly urge said retainer into contact with said valveto provide a seal when said valve resides in said valve seat; and (h) aspring retainer means mounted on the second end of said housing engagingsaid spring means and retaining said spring means in said housing. 2.The checkvalve of claim 1 wherein said valve is a solid disk.
 3. Thecheckvalve of claim 1 wherein said valve retainer has a conical shapeand said valve is an O-ring mounted on said conical-shaped valveretainer.
 4. The checkvalve of claim 3 wherein said valve retainer has agrooved surface.
 5. The checkvalve of claim 1 wherein a threaded fittingis attached to the inlet end of said conduit.
 6. The checkvalve of claim1 wherein the outside edges of said valve are in slideable contact withthe inside surface of said housing.
 7. The checkvalve of claim 1 whereinsaid orifice has a diameter of between about 0.125 inch and 0.25 inch.8. A method for dispersing a fluid in a liquid stream which comprises:(a) flowing said fluid through a passage in a conduit; (b) exiting saidfluid from said passage through an orifice; (c) displacing a valve froma valve seat circumscribing said orifice with said flow of fluid; (d)urging said valve against a valve retainer to move said valve retainerlongitudinally in a slotted housing having openings in opposition to aspring means compressing said spring means; and (e) passing said fluidpast said valve and through slots openings in said slotted housing anddispersing said fluid into said liquid stream flowing past and throughsaid slotted housing; and (f) flushing said valve, said valve retainer,and said spring means by passing a portion of said liquid stream aroundsaid valve, said valve retainer, and said spring means.
 9. The method ofclaim 8 wherein said liquid stream comprises irrigation water and saidfluid comprises an agricultural chemical selected from the groupconsisting of herbicides, pesticides and fertilizers.
 10. The method ofclaim 8 wherein upon termination of the flow of said fluid the springmeans acts to return said valve retainer and valve longitudinally insaid slotted housing and urge said valve against said valve seat to sealsaid orifice.
 11. A checkvalve for dispersing a fluid into a stream ofliquid said checkvalve comprising: (a) a conduit having a passageextending longitudinally therethrough, said passage providing an inletend and an outlet end to said conduit; (b) an orifice located at theoutlet end of said passage; (c) a housing having a first end fixed tothe outlet end of said conduit, said housing having a plurality ofopenings extending substantially the length of said housing to allow aportion of the liquid flowing past said housing to flow through saidhousing; (d) a valve seat within said housing circumscribing saidorifice: (e) a flat valve slidably mounted in said housing and adaptedto reside in said valve seat; (f) a valve retainer slidably mounted insaid housing and adapted to urge said flat valve against said valveseat; (g) a spring means in said housing operatively connected to saidvalve retainer to yieldingly urge said retainer into contact with saidflat valve to provide a seal when said flat valve resides in said valveseat, and (h) a spring retainer means mounted on the second end of saidhousing engaging said spring means and retaining said spring means insaid housing; wherein at least one of the plurality of openings in saidhousing provides for flushing of said flat valve, said valve retainer,said spring means, and said spring retainer means by said stream ofliquid.
 12. The checkvalve of claim 1 wherein at least one of theplurality of openings in said housing provides for flushing of saidvalve, said valve retainer, said spring means and said spring retainermeans by said stream of liquid.
 13. The checkvalve of claim 1, whereinat least one of the plurality of openings in said housing provides fordispersing said fluid into said liquid stream.
 14. The checkvalve ofclaim 1, wherein at least one of the plurality of openings provides forflushing of said valve, said valve retainer, said spring means, and saidspring retainer and for dispersing said fluid into said liquid stream.15. The method of claim 8, wherein said valve is a flat valve.
 16. Thecheckvalve of claim 11, wherein the at least one of the plurality ofopenings in said housing provides for dispersing said fluid into saidliquid stream.